Examples of known molding systems are (amongst others): (i) the HyPET™ Molding System, (ii) the Quadloc™ Molding System, (iii) the Hylectric™ Molding System, and (iv) the HyMet™ Molding System, all manufactured by Husky Injection Molding Systems (www.husky.ca).
U.S. Pat. No. 4,029,457 (Inventor: Yamamoto; Published: 1977 Jun. 14) discloses a molding machine of the type where a movable die plate carrying a movable mold is moved toward a stationary mold. The movable die plate is locked, by a locking member, to the tie bars. Then the mold-tightening cylinder is operated to strongly urge the movable mold against the stationary mold. The locking member is operated by an electric actuator before the movable mold engages the stationary mold, or while the movable die plate is still being moved toward the stationary mold.
U.S. Pat. No. 5,211,970 (Inventor: Sakurai et al; Published: 1993 May 18) discloses a hydraulic clamping apparatus for use with injection molding machines. The clamping apparatus includes (i) a first hydraulic actuator having a first cylinder and (ii) a first hollow, cup-shaped piston with a closed head portion disposed for reciprocating movement within the first cylinder, (iii) a foot portion axially spaced from the head portion and defining an opening, (iv) a second hydraulic actuator having a second piston, (v) a rod extending axially through the opening into the first piston and connected between the first and second pistons, (vi) a second cylinder mounted for reciprocating movement on the second piston and through the opening between a recessed position substantially within the first piston and an extended position substantially outside the first piston, and (vii) a clutch operable in the extended position of the second cylinder to produce engagement thereof with the first piston. The overall length of the apparatus is minimized by placement of the second actuator cylinder within the first piston.
U.S. Pat. No. 5,320,517 (Inventor: Hirata et al; Published: 1994 Jun. 14) discloses a clamping system for a molding press that has: (i) a moving plate with clamping cylinders each with a bore to take a rod attached to a piston, and (ii) a compensator device between two oil chambers. More specifically, a clamping apparatus of a molding machine is disclosed that includes: (i) a base, (ii) a fixed board disposed on the base, (iii) a movable board movable relative to the fixed board, (iv) a plurality of mold clamping cylinders disposed in predetermined positions of the fixed board, the mold clamping cylinders each having a mold clamping piston with a tie bar reception hole and a tie bar connection device disposed on the mold clamping piston, (v) a plurality of tie bars with a thread at their one end, the tie bars being disposed in correspondence with the mold clamping cylinders on the movable board, (vi) a plurality of mold opening/closing cylinders for moving the movable board, and (vii) an axially movable sleeve associated with each clamping cylinder for adjusting an axial position of an associated piston to adjust an engagement position of the tie bar connection device. The sleeve is disposed in an opening in the fixed board and forms an extension of the tie bar reception hole, with one end of the sleeve abutting against a reception wall provided in each piston surrounding the tie bar reception hole. The other end of the sleeve threadably cooperates with an engagement adjustment screw ring that is secured to the fixed board.
U.S. Pat. No. 5,338,171 (Inventor: Hayakawa et al; Published: 1994 Aug. 16) discloses a mold clamping device with an aligning device that includes a fixed die plate with mold clamping hydraulic cylinders, and hollow pistons and tie-bars, connected through an aligning mechanism. More specifically, a molding apparatus is disclosed with die-clamping and alignment devices that has: (i) a stationary die plate for holding a stationary die, (ii) a movable die plate for holding a movable die, (iii) a device for moving (forward and rearward) the movable die plate with respect to the stationary die plate, (iv) a fastening device for fastening the movable die plate and the tie bar to each other by hydraulic force when the stationary die and the movable die have been approached to predetermined positions, (v) a tie bar for clamping the movable die and the stationary die by die-clamping force generated by a die-clamping cylinder, and (vi) a primary alignment mechanism provided for at least one junction among junctions between a piston of a die-clamping hydraulic cylinder and the tie bar, between a support plate and the tie bar, and between the movable die plate and a movable die plate support member, in order to permit the two dies to be aligned to each other by a secondary position alignment function, such as a guide pie for aligning the two dies at the time of clamping the dies.
U.S. Pat. No. 5,439,369 (Inventor: Wang; Published: 1995 Aug. 8) discloses a mold-locking device for an injection molding machine. The device includes a stationary disc and a movable disc displaceable to lock a mold placed between the stationary disc and the movable disc. Four oil cylinders are provided to move the movable disc on four guide rods back and forth. Four push rods are provided, each having a front end secured to the movable disc and a rear end extending through four cylindrical tubes disposed with a respective one of four holes formed in a support disc. A piston disposed within a piston chamber formed in a front surface of the support disc is pushed forward to respectively push a shield plate. The shield plate displaces the four push rods so as to push the movable disc with a great force, after the movable disc has been pushed forward to lock the mold stably.
U.S. Pat. No. 5,645,875 (Inventor: Glaesener et al; Published: 1997 Jul. 8) discloses a securing/clamping assembly for clamping platens of an injection molding machine. The assembly includes a mechanism for guiding the platens and a body member having a structure which is movable as a single unit. The body member is adapted to be attached with at least one of the platens and includes a mechanism for securing the mechanism for guiding and for conveying a clamping force to the platens for clamping the platens during injection molding. The mechanism for securing includes an engagement mechanism for placing the mechanism for securing into and out of locking engagement with the mechanism for guiding, such that when the engagement mechanism is out of locking engagement with the mechanism for guiding, the body member and the mechanism for guiding are relatively movable.
U.S. Pat. No. 5,868,989 (Inventor: Glaesener; Published: 1999 Feb. 9) discloses a securing/clamping assembly for clamping platens of an injection molding machine, which includes: (i) a mechanism for guiding the platens, and (ii) a body member that has a structure which is movable as a single unit. The body member is adapted to be attached with at least one of the platens, and includes a mechanism for securing the mechanism for guiding and for conveying a clamping force to the platens for clamping the platens during injection molding. The mechanism for securing includes an engagement mechanism for placing the mechanism for securing into and out of locking engagement with the mechanism for guiding, such that when the engagement mechanism is out of locking engagement with the mechanism for guiding, the body member and the mechanism for guiding are relatively movable.
U.S. Pat. No. 5,776,516 (Inventor: Armbruster et al; Published: 1998 Jul. 7) discloses a two-platen injection molding machine with a stationary mold carrier plate and a movable mold carrier plate which are connected via tie bars having piston-cylinder units which build up and cancel the clamping force. At least one driving cylinder is arranged at the carrier plates for quick driving movement thereof. The tie bars are constructed as loose clamping pins forming the piston rod of the piston-cylinder units. The tie bars are guided through the movable mold carrier plate and the stationary mold carrier plate, and have a hydraulic high-pressure closing unit and a quick-locking mechanism mounted thereon external to the mold carrier plates. Elements are provided which detect the position of the movable mold carrier plate in a defined manner and control the quick-locking mechanism, the closing unit, and the driving cylinder.
U.S. Pat. No. 5,922,372 (Inventor: Schad; Published: 1999 Jul. 13) discloses a securing/clamping system for use with platens of a molding machine, which includes: (i) a stationary platen having a first mold half affixed thereto, (ii) a movable platen having a second mold half affixed thereto (the movable platen travels along a plurality of tie bars, and reciprocatively moves between a mold open and mold closed position), and (iii) a system for applying a clamping force to the movable platen.
U.S. Pat. No. 6,093,361 (Inventor: Schad; Published: 2000 Jul. 25) discloses stationary and movable platens that have mold halves affixed thereto. The movable platen is reciprocatingly moved between a mold open and a mold closed position, and a clamping force is applied to the movable platen in the mold closed position, and a mold break force is applied to the movable platen in the mold closed position. At least one column is provided having a first end affixed to the movable platen, and a threaded rod engages a threaded member which is operatively connected to the column.
U.S. Pat. No. 6,120,724 (Inventor: Glaesener; Published: 2000 Sep. 19) discloses a mold stroke force that is applied to the movable platen to move the movable platen between a mold open position and a mold closed position and from the mold closed to the mold open position. A mold break force is applied to the movable platen in the mold closed position to break open the mold. The mold stroke cylinder for applying a mold stroke force acts inside the mold stroke cylinder for applying a mold break force.
U.S. Pat. No. 6,241,509 (Inventor: Galt et al: Published: 2001 Jun. 5) discloses a tie bar construction for low tonnage injection molding machine requiring less parts and providing more space. A stationary platen and a movable platen movable with respect to the stationary platen from a closed position in clamping engagement with the stationary platen to an open position spaced from the stationary platen. At least two tie bars are provided connecting the stationary platen to the movable platen, and a stroke cylinder within each tie bar operative to move the platens from an open to closed position and from a closed to open position. Clamping means are provided to clamp the platens together in the closed position, and including means carried by the tie bars to engage the clamping means.
U.S. Pat. No. 6,533,573 (Inventor: Tamaki et al; Published: 2003 Mar. 18) discloses a mold clamping apparatus for an injection molding machine includes a stationary platen fixedly holding the stationary mold, a movable platen fixedly holding the movable mold and disposed opposite to the stationary platen, tie bars for guiding the movable platen for movement toward and away from the stationary platen, a movable platen driving mechanism for moving the movable platen along the tie bars to close and open the mold, a movable platen fixing mechanism for fixing the movable platen to the tie bars at a set position immediately before a position where the movable mold is joined to the stationary mold, and a clamping force applying mechanism including sealed hydraulic cylinder actuators capable of converting energy of a hydraulic fluid into an intensified mold clamping force and of applying the intensified mold clamping force to the stationary platen. In one embodiment, a rear plate located behind the movable platen carries a hydraulically driven ram support and clamping ram, and the ram support has a piston portion that is carried in a cylinder bore in the rear plate. The ram hydraulically clamps the mold closed after the movable platen is electrically driven to bring the mold halves together.
U.S. Pat. No. 6,767,204 (Inventor: Fuller; Published: 2004 Jul. 27) discloses an interlock for a column that includes a piston with a piston rod, such that the piston rod is disposed in a claw bush. The claw bush is disposed in a single- or multi-part plate, such that the piston and the claw bush can move in the single- or multi-part plate. In one embodiment, the claw bush has at least two stages, to apply the force in a distributed manner, the contour of the stages corresponding to the end of the piston rod and/or to the end of the column, the average radius of the first stage differing from the average radius of the second stage.
U.S. Pat. No. 6,811,388 (Inventor: Kitayama et al; Published: 2004 Nov. 2) discloses a mold clamping unit employed in an injection molding apparatus for opening and closing a mold having a movable mold plate and a fixed mold plate. The mold clamping unit includes a mold clamping cylinder, mold opening means for applying a mold opening force of a predetermined magnitude to the movable mold plate in the direction from the closed position to the fully open position and moving the movable mold plate from the closed position to the predetermined half-open position located between the closed position and fully open position, and switching means for switching the mold clamping force generated by the mold clamping cylinder between the first mold clamping force which is larger than the mold opening force and a second mold clamping force which is smaller than the mold opening force by switching the supply pressure of working fluid supplied to the mold clamping cylinder. In such a configuration, special mold opening means for moving the movable mold plate from the closed position to the half-open position is provided separately in addition to the mold clamping cylinder. As a result, the movable mold plate can be accurately moved to the half-open position.
U.S. Pat. No. 6,893,250 (Inventor: Meschia et al; Published: 2005 May 17) discloses an injection molding machine including a fixed mold half mounted on a fixed plate integral with the machine frame and a moveable mold half mounted on a moveable plate supported in translation on the machine frame and guided along guide columns integral with the fixed plate, to pass from a mold closing position to a mold opening position, and a closing and clamping system including clamping means, integral with the moveable plate and acting on a portion of the guide columns to lock the moveable plate in the closing position. The clamping means includes a plurality of locking inserts mounted slidably within seats of a body integral with the moveable plate to pass from a non clamping position to a clamping position in which they act, in a locking relationship, on the guide columns, each locking insert having a circular hole to receive an eccentric shaft in an eccentric position, so that rotation of the eccentric shaft causes translation of the insert, drive means being provided such as to set the eccentric shafts in rotation synchronously to allow opening/closing of the clamping means.
U.S. Pat. No. 6,945,765 (Inventor: Roetzel; Published: 2005 Sep. 20) discloses a clamp that includes a tie-bar which extends between a fixed and a movable platen of a molding machine, with respect to the first, and hydraulically operated locking means for engaging the tie bar and generating the clamping force. The locking means includes a hydraulic cylinder having a hollow sleeve and piston provided with internal toothings, in axially spaced apart positions. The sleeve and piston unit is made to rotate and slide axially, to selectively engage and disengage with the toothed head at the end of the tie bar to allow step and fine adjustments of the position of the movable platen, in relation to the thickness of the mold.
United States Patent Application Number 2005/0287246 (Inventor: Looije; Published: 2005 Dec. 29) discloses a clamp piston assembly that includes a body portion in which a pocket is provided. The pocket is arranged to receive an insert in the form of a rotatable clamp bushing. Sets of blades or wear pads are positioned on both an internal surface of the pocket and the external surface of the clamp bushing and cooperate to form sealable chambers that extend about the circumference of the clamp bushing. These chambers are in fluid communication with suitable processor-controlled valves and hydraulic or pneumatic pumps that operative to purge and inject fluid from and into the chambers. Pressurized fluid acting within selected chambers causes rotation of the clamp bushing. The insert also contains a row of teeth arranged to selectively engage corresponding teeth in a tie-bar. The clamp bushing is hence independently rotatable from its surrounding body that, in use, is mechanically attached to an injection molding machine.
European Patent Number 1,287,967 (Fuller et al; Published 2003 Mar. 5) discloses a locking system for a column or tie bar of an injection molding machine. The locking system includes a bush with internal steps shaped to correspond with the tie bar end.
Great Britain Patent Number 1,601,419 (Assignee: Warnke Umformtech; Published: 28 Oct. 1981) discloses a mold closing and locking arrangement in an injection molding machine having two mold mounting platens. One of the platens is guided on the machine bed and is movable with respect to the other platen in the closing direction and the opening direction of the mold. Working cylinder/piston units are used to bring together and separate the two mold mounting platens. A locking device is used which causes the two mold mounting platens to be clamped together in the closed position. An apparatus is also disclosed for generating the closing force and the clamping force.